Soil Temperature for Germination

as posted on An Iowa Mom Videos

(If you use a glass soil thermometer, you can start the hole with a screw driver so you don't break the glass.)

Read early morning several days in a row and average the temperatures.

I found lots of variations in temperature planting charts. I averaged the results of several charts I found online. I listed warmer (safer) if conflicting results were close. These are temperatures if you poke the thermometer in ground about 4-6 inches.

Plant when soil (4"-6" deep) is not less than these temperatures:

  • 45° F : radish, peas, lettuce, spinach, kale, parsnips

  • 50° F: onions, leeks, turnips, chard

  • 60° F: beans, beets, carrots, corn, marigolds

  • 70° F: cucumbers, squash, melons, basil

  • 75° F: pumpkins, okra

If you plant early you may need to do some replanting, however, it also will give a better chance for a longer harvest season. If seedling emerge during a frost, cover with a sheets or fabric drop cloths (Do not use plastic).

Transplant tomato, eggplant and peppers... Some charts say 60°, 70° & 75°

I plan to plant mine when the air is consistently warm (all danger of frost is gone) and the ground is 70° and cover them with plastic gallon jugs until the plant fills the jug.

http://expresshim.com/plantingtemp.html (feel free to print)